newmom21C, I personally have the problem of leaving to go get a tissue and forgetting what it was I was doing by the time I get there. There was an article that got a lot of press a year or two ago for showing that walking through a door was a trigger for losing your train of thought. Since I read that article, if I leave to go do something in another room, I try to be consciously thinking of what I am going to do as I walk through the door. I have no idea if this is just a placebo effect, but it does seem like I forget less by using this strategy. You might want to share it with your DD, and show her the article if you can find it.
